Minako, a Tokyo housewife, is depressed that everyone has an active life outside the home except her. Taking her inspiration from TV reports of a hitch-hiking chainsaw murderer, Minako decides to spice up her life by finding a young lover and running off with him by faking her kidnapping. While her family frets and worries, Minako has a wonderful time. Eventually, though, she decides it's time to go back to her family. Her lover, however, isn't ready for the fun to end, and Minako's fake kidnapping soon becomes all too real.

A ship runs aground on a mysterious atoll leading to an investigation by insurance representative Kusanagi, who discovers an ancient bead that he gives to his daughter Asagi. Meanwhile, ornithologist Nagamine investigates reports of a new species of large bird named Gyaos. As the Gyaos begin to attack, an ancient guardian with a bond to Asagi emerges.

A strange meteor lands in Japan and unleashes hundreds of insect-like "Legion" creatures bent on colonizing the Earth. When the military fails to control the situation, Gamera shows up to deal with the ever-evolving space adversary. However the battle may result in Gamera losing his bond with both Asagi and humanity.

The Girls' Division of Okinawa Normal School and the First Okinawa Prefectural High School for Girls were also known as "Himeyuri no Gakuen". In July 1944, the students, who were supposed to spend their summer vacations at home, were called back to school to prepare for the coming war and to fulfill their duties as subjects of the Imperial State. The fate of the girls and teachers awaited them as the American army attacked.